This invention relates generally to air filter support systems, and more particularly, to modular air filter systems for clean rooms wherein the number of particles in the air must be minimized.
Clean rooms are commonly used in many industries, such as the electronic, medical and pharmaceutical industries, to reduce the number of particles in the air to specified limitations. In the most common approach, a layer of flat filters is suspended from a room ceiling or a sidewall, with the filters extending over the entire area of the ceiling or sidewall. The air is conducted from a plenum through the filters into an open space in the room and then returned back to the plenum by way of outlets in the room. The filter elements are normally supported by supporting elements, such as a grid, which engages the entire peripheral frame of each filter element. In addition, it is necessary to have an air-sealing gasket or sealing gel positioned between the grid elements and the filter panel frames. Because the known grid support systems do not always work efficiently, numerous attempts have been made to provide improved filter systems and/or support systems for clean rooms.
In U.S. Pat. No. 5,329,739 to Madl, Jr., there is described a clean room filter system in which clusters of four filter units are support together at the intersection of respective corners by a rotatable disk overlapping each corner. Each disk is suspended from a support surface, such as a ceiling, and includes holes which are alignable with holes in the frames at the four corners, whereby vertical positioning pins may be threaded into the supporting disk and entered into respective corners of the filter panels to hold the filter panels in place. The vertical positioning pins are retracted when a disk is to be rotated, and a pie-shaped cut-out portion formed in the disk is aligned with a filter panel corner so that the filter panel may be inserted or removed from the plane of the remaining filter panels without disturbing any of the adjacent filter panels. The positioning pins are reinserted when the disk is returned to its full support position, with the openings in the disk aligned with the openings in the filter panel frames. Gel sealant carried on sealing strips seals the filter units against unfiltered air leakage.
U.S. Pat. No. 5,871,556 to Jeanseau et al. discloses a clean room ceiling in which individual filter units are suspended solely by unshared suspension assemblies so as to be self supporting and readily installable and removable individually and free of grids and other multiple unit supporting expedients. The unshared suspension assemblies are mounted centrally of each filter unit between separate filter packs on each side of a divider.
However, it is still desirable to provide improved and simplified filter support systems for clean rooms.
The pre sent invention provides clean room filter support systems that may be used in a ceiling or sidewall, and which are less cosutly, better performing and faster to install. The present invention provides more flexible support systems than any currently available, and includes a plurality of individual filter modules, each complete unto itself, including an upper housing or lid panel that may be separable, a volume control or shut off damper, and framed filter elements or panels. Additionally, light fixtures and diffuser panels, or airfoil frame means may be added. The present invention includes a plurality of spaced support members that are suspended from a ceiling or other supporting surface, so as to support corners of individual filter modules where they meet at a corner, at an intersection, or at a wall. Each supporting element includes a support rod and one or more unique support brackets for laterally supporting a filter module, with or without separable lid panels, or a blower housing. Each filter module includes a filter frame that is sufficiently rigid, so as to support filter panels therein when a series of filter modules we secured together in the unique supporting brackets. Each filter module is independently supported at least at the bottom, and can be installed or removed from within the room, without effecting adjacent filter modules.
Filter modules of the present invention can have integrated or separable lid panels, and/or be of the ducted filter-type, fan powered filter-type, or pressure plenum-type. All variations may be interchanged or mixed within a ceiling filter system of the present invention. The top surface or lid panel of each filter module, whether ducted, fan powered, or directly connected to a pressure plenum, may be independent of or separable from the filter element, and installed prior to the filter element. When separable lid panels are used they form a barrier between the clean room space below and the plenum space above. Due to the use of these separable lid panels, the amount of time needed to achieve isolation of the clean space in the room is less than with other known filter systems.
Supply air duct work for the ducted filter module variation is attached directly to the upper side of the lid panel of each module, thus making the duct connection independent of the filter element in the module when the separable lid panel option is used. Preferably, each ducted filter module lid panel includes a damper at the supply duct connection to vary the volume of supply air for balancing and fine-tuning. When the entire filter assembly or module is complete, the rigidly fastened separable lid panels make the entire system a structural diaphragm, thereby reducing the need for further seismic supports. Each of the filter modules may be inserted and removed from within the room, while the system remains in operation by merely shutting off one or more individual modules by use of the dampers.
Gaps between adjacent separable lid panels and/or filter modules are sealed. And, joints between separable lid panels and filter elements are sealed with gaskets or gel sealants.
It is, therefore, a general object of the present invention to provide an improved and simplified air filter system for a clean room. It is a particular object of the present invention to provide an improved and simplified clean room air filter system comprised of individual modules. It is another particular object of the present invention to provide an improved and simplified clean room air filter system comprised of separate filter modules having separable lid panels and filter elements. It is yet another particular object of the present invention to provide an improved and simplified clean room air filter system which utilizes support rods suspended from an overhead ceiling, or other support structure, having one or more spaced support brackets thereon to which filter modules, and/or separable lid panels, or blower housings and filter elements are laterally secured.
These and other objects of the present invention are achieved by providing an air filter system having a plurality of filter modules supported by a plurality of spaced support rods secured to a ceiling or other support surface, with one or more support brackets mounted on each support rod. Each filter module includes a lid panel, which may or may not be separable, having means for allowing air to be blown from an air supply system therethrough. Filter elements, having rigid frames with filter panels held therein, are held in the lid panels and laterally secured to the support brackets. When the lid panels are separable they are supported at their corners by separate support brackets held in upper positions on four spaced support rods, while the separable lid panels have filter elements inserted below each lid panel. The separable lid panels are laterally secured to upper support brackets, while the filter elements are laterally secured to lower support brackets, on each of the four support rods. Adjacent lid panels and filter elements are mounted in the same way to form an air filter system. In one embodiment of the invention, lights are secured to the filter element and diffuser panels are secured below the lights by arms secured to lower brackets on the support rods. Or, the filter frames may include shaped lower edges to close the lower joint between adjacent filter modules.